Reenforced bag closure



Oct. 16, 1934.

w. N. BAKER v 1,977,298

REENFORCED BAG CLOSURE Filedoot. 29, 1931 INVENTOR BY y ATTORNEY Patented Oct. 16, 1934 UNITED STATES PATENT OFFICE REENFORCED BAG CLOSURE Application October 29,1931, Serial No. 571,761

8 Claims.

, This invention relates to an improved, reenforced closure for the ends of bags of various sorts. It may be employed in connection with the upper end of a valve bag, or to close an open mouthed bag after it is lled, or to close the bottoms of either of these types of bags. It is particularly useful in connection with multiwall paper bags which are subjected to heavy strains in use, as for example bags used in the shipment of cement or the like, although the invention is applicable to single wall bags and those formed of materials other than paper.

A feature of the invention is the provision of reenforcing strips at the ends of a bag in such a way that a desired yielding effect is produced which will relieve the strain upon the fastening meansI when the bag is tossed about in a lled condition. For this purpose a plurality of exible reenforcing strips are preferably provided on each side of the bag along its end, the fastening devices passing through all of the strips. The outer strips in this case are preferably narrower than those beneath so as to provide a stepped effect which affords greater flexibility. A-single strip may be employed on one or both sides, if desired, but in this case it should be of suiiicient width to extend substantially beyond the fastening elements and should be relatively stiff but yielding. The reenforcing strips contemplated are particularly applicable to a bag having butted ends which are secured by staples although they are also applicable to sewn bags. 'I'he necessity for the provision of a yielding construction to prevent undue strains which would result in tearing the paper is greater in a stapled bag than in one which is sewn due to the fact that the thread will stretch in a sewn bag. In either type of bag, however, the added yielding quality of the closure will increase the strength and y life of the bag.

Other features and advantages of the inven-I tion will appear from the detailed description of an illustrativeform of the same which will now be given in conjunction with the accompanying drawing in which:

Fig. 1 is a face view of a bag embodying the features of the invention.

Fig. 2 is an enlarged, transverse, sectional view taken along the line 2-2 of Figure 1.

Fig. 3` is a similar view showing a modified construction, and

Fig. 4 is a detail, face view of a'corner of a modified valve construction.

Referring now to the drawing there is shown a bag formed by a tubular member ,10 having gussets at its sides extending inwardly to the lines- 11 and 12 of Figure 1. Member 1li-may be formed in any convenient way from paper or other flexible material and may be of single or multi-wall construction. Its ends may suitably be cut square across. The upper end of the gusset at the right may be folded inwardly as shown to form a valve having an opening at 13 and an inwardly extending portion 14. In order to increase the length of the inward extension 14 the upper edges of the tube may be provided with slits near the gusset at the valve side of the bag which, upon forming the valve, will produce shoulders 15 and 16 at right angles to each other. These slits may be omitted, if desired, and the valve may be formed by simply folding the end of the gusset inwardly as shown in Figure 4. In this construction the inner end 17 of the valve extension will terminate along a line perpendicular to the end of the bag at the upper corner 18 of the valve opening. For this reason the formation shown in Figure 1 is somewhat preferred since there is less likelihood that the valve will be forced open when the bag is tossed about in a lled condition. In either construction the walls 19 and 20 of the tubular member are simply brought together in a butted relation at their outer ends. In lieu of simply slitting the end of the bag as shown in Figure 1, it will be apparent that a section of the tube may be simply cut away, in the well known manner, so that the tube prior to folding the end will have the valve portion extending beyond the remaining portion of the tube to an extent equivalent to the length of the shoulder 16.

A sealing strip 21 formed of any suitable, tough, flexible material may be applied over the butted ends of the tube to completely close oi and prevent sifting between the walls. For this purpose a strip of creped kraft paper or similar material will be particularly satisfactory although either a heavier or a lighter material may be used. It should in any case be sufficiently flexible to permit it to be freely bent around the -ends of the bag walls and it should be relatively tough. The strip should be of such length as to extend completely across the bag from the left edge to a point slightly beyond the shoulder 15 of Figure 1 or the point 18 of Figure 4. It should be of sufficient width to extend down along each wall of the bag, say an inch or more.

Against the outer surfaces of the sealing strip there is provided, on each side of the bag, one or more strips 22 of stiffer, reenforcing material. 110

For this purpose a kraft board of suitable weight such as a thir'ty point board weighing approximately lbs. per thousand square feet will be found to be quite satisfactory. Either heavier or lighter members may be employed, however and they may be formed of materials other than cardboard or pasteboard. Any suitable form of fastening device may be employed to secure the various parts together. Staples 23 have been indicated for this purpose in the drawing. These are particularly effective and appropriate where the reenforcing members employed are of such a nature that sewing is rendered difficult or impossible. If a plurality of the strips 22 is employed on each side of the bag they are preferably arranged in stepped relation, as Shown, the innermost members extending below the outer members. This will provide a desirable yielding` action in the spreading of the walls 19 and 20 in response to a heavy strain. The resistance to the separation will be gradually built up as more of the reenforcing strips are exed and in this way the development of a sudden tearing strain is avoided. The strips 22, particularly the innermost, should be of sufficient width to extend some distance, say half an inch or so, beneath the lowermost line of fastening devices, and each superposed strip should terminate a quarter of an inch or so from the edge of the strip next below. This will insure a desired flexibility or yield in the joint which will prevent transmission of the shocks directly to the fastening devices. While two reenforcing strips are shown on each side of the bag it will be understood that a greater number, preferably all in stepped relation, may be employed if desired. A single strip, if formed of sufciently stii and tough material, may be found quite effective as a reeinforcing agent when extended somewhat beyond the lower line of fastening elements so as to yieldingly resist the separation of the bag walls in the manner explained. If staples are employed to secure the parts they may be arranged in any suitable way as in a pair of horizontal lines, as shown, or in a single line of this sort or in one or more rows in which the staples are arranged at an angle to the end of the bag.

In Figure 3 there is shown a modified construction in which the sealing strip 21 has been omitted. To completely seal the end of the bag and prevent sifting there is provided a layer of paste or similar sealing material 24 between the opposed faces of the walls 25 and 26. This paste which extends across the entire end of the bag covered by the reenforcing strips is preferably placed only beyond the line or lines of staples 27 or similar fastening means. It therefore, will not be subjected to any particular strain since any tendency to pull the walls of the bag apart will be taken up first by the yield of the s rips 22 and then more completely by the fastening devices 27. The paste may be applied in any suitable way as by spreading it over the end of one wall of the bag prior to butting it with the opposite wall. The paste may, if desired, be supplemented by the use of a sealing strip such as the strip 21 or the latter may be pasted over the end of the bag as itl is applied. If the bag is not to be used in the shipment of granular or pulverent materials the sealing means may be eliminated altogether, if desired.

The lower end of the bag may be formed in any of the ways described'in connection with the the bag except, 6I course, at the corner which is 85 valved. Here at least one fastener should be passed through the upper corner of the inturned valve extension, as shown in Figures 1 and 4. A simple sack having no gussets may similarly have its bottom, as well as its open mouth after filling, closed in the same way.

While an illustrative form of the invention and various modifications have been disclosed in'. some detail in the foregoing it will be understood that other changes may be made in the form and arrangement of the parts without departing from the general spirit and scope of the invention as defined by the claims.

I claim:

1. A closure for a bag having the free ends of its walls butted which comprises sealing means for preventing the escape of material between said butted walls, relatively stili. reenforcing strips arranged in stepped relation adjacent the butted ends of said walls, and fastening means for securing said strips to said walls.

2. A closure for a bag having the free ends of its Walls butted which comprises sealing means for preventing the escape of material between said butted Walls, relatively stiff reenforcing strips adjacent the butted ends of said walls, said strips being arranged in stepped relation on each side of the bag, and fastening means for securing said strips and sealing means to said Walls.

3. A bag closure comprising butted side Walls,

a sealing strip enclosing the butted ends of said side walls, staples for securing the ends of said walls and sealing strip together, and relatively stiff but yielding means associated with said staples for absorbing a portion of the strains transmitted to said staples, the ends of said sealing strip extending below said yielding means.

4. A bag closure comprising butted side walls, sealing means between the butted ends of said side walls, fastening means for securing said walls adjacent said sealing means, and a plurality of yielding reenforcing means arranged in stepped relation associated with said fastening means for absorbing a portion of the strains transmitted to said fastening means.

5. A bag closure comprising butted side walls,

a sealing strip enclosing the butted ends of said side walls, fastening means for securing said Walls adjacent said sealing strip, and a plurality l of yielding reenforcing means arranged in stepped relation associated with said fastening .means for absorbing a portion of the strains transmitted to said fastening means.

6. A bag comprising a gus etted tubular member having the end of one gusset bent inwardly to form a valve, the opposite walls of said member being brought together at their ends, a sealing strip enclosing the ends of said walls, rela.- tively stiff reenforcing strips along the walls adi jacent their ends, said sealing strip extending below the ends of said reenforcing strips and staples for securing saidy strips and said walls together.

7. A bag closure comprising butted side walls. l-

bent inwardly to form a. valve, the ends' of the side walls of said member being brought together in butted relation, sealing means between the ends of said side walls, fastening means for securing said walls together adjacent said sealing means, a plurality of reinforcing strips along said side walls adjacent their ends, said reenforcing strips being arranged in stepped relation for absorbing a portion of the strain transmitted to said fastening means.

WEBSTER NOYES BAKER. 

